Hybrid control combining nonlinear and PD for missile

A novel hybrid control approach of combining nonlinear H_∞ and PD (Proportional + Differential) for missiles systems with external disturbances and uncertainties is presented. An explicit solution to the nonlinear H_∞ attitude control problem can be obtained by combining backstepping and variable structure control techniques. The attitude controller achieves good performance, and the unknown disturbances are attenuated. PD controller can guarantee the desired trajectory tracking in the outer loop. Finally, nonlinear six-degree-of-freedom simulation results for the missiles model are presented to demonstrate the effectiveness of the proposed control law.